For switching viewing angles of a liquid crystal display, we proposed to place a liquid crystal device between an
LED and a light-guide of a backlight. The first key component for this configuration is a light source with
electronically-controlled emission angles. Here, we construct such a device by stacking an optical film and a polymer-network
liquid crystal (PNLC) cell on top of a chip-type LED. The optical film contains opaque parallel plates that
limit the LED output in a narrow angular range. The PNLC cell either transmits or scatters the light emerging from the
optical film. Experiment using a 15μm-thick PNLC cell shows that the angular distribution becomes 2.3 times wider
by turning off the PNLC cell. We place this light source at one end of a light-guide so that the angular distribution of
the light propagating inside is controlled. The second key component is some types of micro-strucrures built on the
light-guide to out-couple the propagating light. We first attached various optical films on a light-guide surface.
Although the angular distribution of the extracted light was switched successfully, light was mostly emitted into an
oblique direction, approximately 60° from the plane normal. Next, we used a half-cylinder in place of the optical
films. The curved surface of the cylinder was attached to the light-guide with a small amount of matching oil, which
constituted an optical window. We measured that the angular distribution of the extracted light decreased to 35°
FWHM from 62° FWHM by turning on the PNLC cell.